Robot step control method, robot control apparatus, and computer readable storage medium

ABSTRACT

A robot step control method, a robot control apparatus, and a storage medium are provided. The method includes: determining an expected support force of two legs of a biped robot according to zero-moment point planning data and actual position data of the two legs at a current moment, and determining a current desired joint posture angle of ankle joints of the two legs and a desired joint position matching an actual leg support state using a compliance control algorithm based on an expected support force of the two legs, and centroid movement planning data, centroid actual movement data, step planning data and actual force data of the two legs at the current moment. In such manner, all-direction compliant controls can be performed on a desired leg pose condition according to the actual motion status of the biped robot, thereby improving the walking stability and terrain adaptability of the biped robot.

CROSS REFERENCE TO REFLATED APPLICATIONS

The present disclosure claims priority to Chinese Patent Application No.202210074131.9, filed Jan. 21, 2022, which is hereby incorporated byreference herein as if set forth in its entirety.

BACKGROUND 1. Technical Field

The present disclosure relates to robot control technology, andparticularly to a robot step control method, a robot control apparatus,and a storage medium.

2. Description of Related Art

With the continuous development of technologies, robot technologies havereceived extensive attention from all walks of life because of its greatvalues in researches and applications. Among them, the control methodsfor biped robots is an important research direction in the controlmethods for robots.

However, during the walking control of a biped robot, due to factorssuch as the simplification of gait planning model, the deformation ofmechanical structures, and uneven ground, the un-matchingness betweenthe leg pose condition of the biped robot when stepping according to theplanned walking trajectory and the actual ground conditions will usuallybe caused, which results in the serious collisions with the ground bythe landing of the biped robot during the single-leg support period andthe generation of the larger inter-leg internal force of the biped robotduring the two-leg support period, and the walking stability of thebiped robot will be affected seriously.

BRIEF DESCRIPTION OF THE DRAWINGS

To describe the technical schemes in the embodiments of the presentdisclosure or in the prior art more clearly, the following brieflyintroduces the drawings required for describing the embodiments or theprior art. It should be understood that, the drawings in the followingdescription merely show some embodiments. For those skilled in the art,other drawings can be obtained according to the drawings withoutcreative efforts.

FIG. 1 is a schematic block diagram of the structure of a robot controlapparatus according to an embodiment of the present disclosure.

FIG. 2 is a schematic diagram of the walking of a biped robot accordingto an embodiment of the present disclosure.

FIG. 3 is a schematic diagram of the pose adjustment of an ankle jointof the biped robot of FIG. 2 .

FIG. 4 is a flow chart of a robot step control method according to anembodiment of the present disclosure.

FIG. 5 is a flow chart of sub-steps included in step S220 of FIG. 4 .

FIG. 6 is a flow chart of sub-steps included in step S230 of FIG. 4 .

FIG. 7 is a flow chart of sub-steps included in step S240 of FIG. 4 .

FIG. 8 is a schematic diagram of the stiffness adjustment of a secondelastic damping control model according to an embodiment of the presentdisclosure.

FIG. 9 is a schematic diagram of the stiffness adjustment of a thirdelastic damping control model according to an embodiment of the presentdisclosure.

FIG. 10 is a schematic block diagram of the structure of a robot stepcontroller according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

In order to make the objects, technical solutions and advantages of theembodiments of the present disclosure more clear, the technicalsolutions in the embodiments of the present disclosure will be clearlyand completely described below with reference to the drawings in theembodiments of the present disclosure. Apparently, the describedembodiments are part of the embodiments of the present disclosure, notall of the embodiments. The components of the embodiments of the presentdisclosure that are described and illustrated in the drawings herein maygenerally be arranged and designed in a variety of differentconfigurations.

Therefore, the following detailed description of the embodiments of thepresent disclosure provided in the drawings is not intended to limit thescope of the present disclosure, but merely represent the selectedembodiments of the present disclosure. Based on the embodiments in thepresent disclosure, all other embodiments obtained by those of ordinaryskill in the art without creative work fall within the protection scopeof the present disclosure.

It should be noted that, in the following figures, similar numerals andletters refer to similar items. Therefore, once an item is defined inone figure, it does not require further definition and explanation insubsequent figures.

In the description of the present disclosure, it is to be understoodthat the orientational or positional relationship indicated by the terms“center”, “upper”, “lower”, “left”, “right”, “vertical”, “horizontal”,“inner”, “outer”, or the like is based on the orientational orpositional relationship shown in the drawings, that in the usualplacement of the product related to the present disclosure, or thatcommonly understood by those skilled in the art, and is merely for theconvenience of describing the present disclosure and simplifying thedescription, rather than indicating or implying that the device orcomponent referred to must have a particular orientation, be constructedand operated in a particular orientation, hence should not be understoodas limitations to the present disclosure.

In the descriptions of the embodiments of the present disclosure, itshould be understood that, relational terms such as “first” and “second”are used only to distinguish one entity or operation from another entityor operation, and do not necessarily require or imply the existence ofany actual relationship or sequence between these entities oroperations. Moreover, the terms “comprising”, “including” or any othervariation thereof are intended to encompass non-exclusive inclusion suchthat a process, method, article or apparatus (device) comprising aseries of elements includes not only those elements, but also includesother elements not explicitly listed or inherent to the process, method,article or apparatus. Without further limitation, an element limited bythe sentence “comprising a . . . ” does not preclude the existence ofadditional identical elements in a process, method, article or apparatusthat includes the element. For those of ordinary skill in the art, thespecific meanings of the above-mentioned terms in the present disclosurecan be understood according to the specific condition.

Some embodiments of the present disclosure will be described in detailbelow with reference to the drawings. The following embodiments and thefeatures therein may be combined with each other while there is noconfliction therebetween.

FIG. 1 is a schematic block diagram of the structure of a robot controlapparatus according to an embodiment of the present disclosure. As shownin FIG. 1 , in this embodiment, a robot control apparatus 10 for a bipedrobot having two legs is provided. In this embodiment, the robot controlapparatus 10 may be configured to control the motion status of the bipedrobot, so that a desired leg pose condition (including a desired legposition and a desired leg posture) of the biped robot that is desiredto represent during moving according to a pre-planned walking trajectoryis substantially matched with the actual ground conditions, so as toreduce the impact force of the foot landing in single-leg support periodof the biped robot, and the inter-leg internal force in two-leg supportperiod of the biped robot, thereby effectively improving the walkingstability and terrain adaptability of the biped robot. In which, therobot control apparatus 10 may be remotely connected with the bipedrobot, or may be integrated with the biped robot, so as to realize themotion control of the biped robot.

In this embodiment, the robot control apparatus 10 may include a storage11, a processor 12, a communication unit 13, and a robot step controller100. The components of the storage 11, the processor 12 and thecommunication unit 13 are directly or indirectly electrically connectedto each other to realize data transmission or interaction. For example,the components of the storage 11, the processor 12 and the communicationunit 13 may be electrically connected to each other through one or morecommunication buses or signal lines.

In this embodiment, the storage 11 may be, but not limited to, a randomaccess memory (RAM), a read only memory (ROM), a programmable read onlymemory (PROM), erasable programmable read-Only memory (EPROM),electrical erasable programmable read-only memory (EEPROM), or the like.In which, the storage 11 is used for storing computer programs, and theprocessor 12 can execute the computer programs correspondingly afterreceiving execution instructions.

In this embodiment, the processor 12 may be an integrated circuit chipwith signal processing capability. The processor 12 may be a generalpurpose processor including at least one of a central processing unit(CPU), a graphics processing unit (GPU), a network processor (NP), adigital signal processor (DSP), an application specific integratedcircuit (ASIC), a field-programmable gate array (FPGA) or otherprogrammable logic devices, discrete gate, transistor logic device, anddiscrete hardware component. The general purpose processor may be amicroprocessor or the processor may also be any conventional processorthat may implement or execute the methods, steps, and the logical blockdiagrams disclosed in the embodiments of the present disclosure.

In this embodiment, the communication unit 13 is used for establishing acommunication connection between the robot controller 10 and otherelectronic devices through a network, and for sending/receiving datathrough the network, where the network includes a wired communicationand a wireless communication network. For example, the robot controlapparatus 10 may obtain a planned walking trajectory for the biped robotfrom a walking planning apparatus through the communication unit 13, andsend motion control instructions to the biped robot through thecommunication unit 13, so that the biped robot moves according to themotion control instructions.

In this embodiment, the robot step controller 100 may include at leastone software function module that can be stored in the storage 11 orsolidified in the operating system of the robot control apparatus 10 inthe form of software or firmware. The processor 12 may be used toexecute executable modules such as software function modules andcomputer programs included in the robot step controller 100 that arestored in the storage 11. The robot control apparatus 10 cab performall-direction compliant controls on the desired leg pose condition ofthe biped robot through the robot step controller 100 at leg positiondimension level and leg posture dimension level according to the actualmotion status of the biped robot, so that both the desired leg positionand desired leg posture of the biped robot can substantially match theactual ground conditions. In such a manner, when the biped robot ismoved according to the desired leg pose condition, the impact force ofthe foot landing in a single-leg support period (the time period whenthe biped robot maintains a single-leg support state) of the bipedrobot, and the inter-leg internal force in a two-leg support period (thetime period when the biped robot maintains a two-leg support state) ofthe biped robot can be effectively reduced, thereby improving thewalking stability and the terrain adaptability of the biped robot.

It can be understood that the composition of the robot control apparatus10 in FIG. 1 is only an example of that of a robot control apparatus,and the robot control apparatus 10 may further include more or lesselements than those shown in FIG. 1 , or have a different configurationfrom that shown in FIG. 1 . Each of the elements shown in FIG. 1 may beimplemented in hardware, software, or a combination thereof.

FIG. 2 is a schematic diagram of the walking of a biped robot accordingto an embodiment of the present disclosure. As shown in FIG. 2 , in thisembodiment, in the whole walking process of the biped robot, there are atwo-leg support state and a single-leg support state. When the bipedrobot is in the two-leg support state, both of the two legs of the bipedrobot are supporting on the ground to ensure that the biped robotremains standing; otherwise, when the biped robot is in the single-legsupport state, one of the legs of the biped robot will be used as thesupport leg to support the biped robot to maintain standing, while theother of the legs of the biped robot will be used as the swing leg thatneeds to change the motion track. The foot on the support leg is thesupport foot currently in contact with the ground, and motion trackchanges of the swing leg includes raising of the swing leg, hanging ofthe swing leg, and landing of the swing leg. Therefore, for one step ofthe biped robot, the corresponding gait cycle will be composed of onetwo-leg support period and one single-leg support period that connectwith each other. The single-leg support period will also consist of aswing leg lifting period, a swing leg hanging period, and a swing leglanding period.

At this time, the contact position of the sole of a raised leg of thebiped robot after landing may be correspondingly selected as the originof the world coordinate system to establish a Cartesian right-handedcoordinate system. The positive direction of the X axis represents theforward direction of the biped robot and the positive direction of the Zaxis is vertical to the ground in the upward direction, and the heightof the specific part (e.g., a certain ankle joint of leg) of the bipedrobot relative to the ground is described through the Z axis. Thepositive direction of the Y axis represents the side motion direction ofthe biped robot.

Thus, the pose distribution (including position distribution and posturedistribution) of each component in the biped robot in the entire worldcoordinate system may be represented through the Cartesian right-handedcoordinate system, so that the robot control apparatus 10 controls thebiped robot to move its components to desired positions and presentdesired postures based on the Cartesian right-handed coordinate system.

FIG. 3 is a schematic diagram of the pose adjustment of an ankle jointof the biped robot of FIG. 2 . As shown in FIG. 3 , when there is anobstacle (the triangle in FIG. 3 that is filled with black) at thelanding position of the lifted leg of the biped robot, if the anklejoint of the lifted leg is moved to the obstacle according to theplanned walking trajectory and represents a corresponding joint planningpose (see the position of the ankle joint and the posture of the solethat are represented by the solid line in FIG. 3 ), it can be clearlyseen that this leg cannot ensure the walking balance of the biped robot,and it is necessary to adjust the joint planning pose of the ankle jointof the leg of the biped robot so as to obtain the desired joint pose(see the position of the ankle joint and the posture of the sole thatare represented by the dotted line in FIG. 3 ) of the ankle joint,thereby ensuring that the biped robot stepping on the obstacle tomaintain the walking balance, so as to reduce the landing impact forcecorresponding to the leg and the internal force between the two legswhen the leg as the support leg to cooperate with the other leg.

In the present disclosure, in order to ensure that the robot controlapparatus 10 can perform all-direction compliant control on the desiredleg pose condition of the biped robot according to the actual motionstatus of the biped robot during the walking of the biped robot, itmakes both of the desired leg position and the desired leg posture ofthe biped robot to substantially match the actual ground conditions, soas to effectively reduce the impact force of the foot landing during thesingle-leg support period of the biped robot and the inter-leg internalforce of the biped robot during the two-leg support period through thedesired leg pose condition, thereby improving the walking stability andterrain adaptability of the biped robot.

FIG. 4 is a flow chart of a robot step control method according to anembodiment of the present disclosure. In this embodiment, the robot stepcontrol method is a computer-implemented method executable for aprocessor of a biped robot (e.g., a humanoid robot). In otherembodiments, the method may be implemented through the robot stepcontrol apparatus 10 shown in FIG. 1 or a robot step controller 100shown in FIG. 10 . As shown in FIG. 4 , in this embodiment, the robotstep control method may include the following steps.

S210: obtaining movement planning data of a centroid of the biped robot,step planning data of two legs of the biped robot and zero-moment pointplanning data of the biped robot at a current moment, and an actual legsupport state, actual movement data of the centroid, actual positiondata of the two legs and actual force data of the two legs at thecurrent moment.

In this embodiment, the movement planning data of the centroid (centerof mass) is used to represent the centroid data corresponding to thepre-planned centroid movement planning trajectory at the current controlmoment of the biped robot, which includes a horizontal movement planningposition of the centroid and a horizontal movement planning velocity ofthe centroid. The horizontal movement planning position of the centroidrepresents the planned movement position (including a position componentof the horizontal movement planning position of the centroid on theX-axis, and a position component of the horizontal movement planningposition of the centroid on the Y axis) of the centroid of the robot onthe horizontal plane where the X-axis and the Y-axis are located, andthe horizontal movement planning velocity of the centroid represents theplanned movement velocity (including a velocity component of thehorizontal movement planning velocity of the centroid on the X-axis, anda velocity component of the horizontal movement planning velocity of thecentroid on the Y axis) of the centroid of the robot on the horizontalplane where the X-axis and the Y-axis are located

The two-leg step planning data is used to represent the leg datacorresponding to the pre-planned pose change trajectory of the two legsof the biped robot at the current control moment. The two-leg stepplanning data includes a joint horizontal planning position and a jointlongitudinal planning position of the ankle joints of the two legs(including the ankle joint of the left leg and that of the right leg),and an inter-leg horizontal expected internal force difference. Thejoint horizontal planning position represents the joint planningposition (including a position component of the joint horizontalplanning position on the X-axis, and a position component of the jointhorizontal planning position on the Y axis) of the ankle joint of thecorresponding leg on the horizontal plane where the X-axis and theY-axis are located; the joint longitudinal planning position representsthe joint planning position of the ankle joint of the corresponding legon the Z axis; the inter-leg horizontal expected internal forcedifference is used to represent the internal force difference betweenthe horizontal expected internal force of the left leg (including aninternal force component of the horizontal expected internal force ofthe left leg on the X-axis, and an internal force component of thehorizontally expected internal force of the left leg on the Y-axis) andthe horizontal expected internal force of the right leg (including aninternal force component of the horizontal expected internal force ofthe right leg on the X-axis, and an internal force component of thehorizontal expected internal force of the right leg on the Y-axis). Inthis embodiment, as an example, the inter-leg horizontal expectedinternal force difference may be zero.

The zero-moment point planning data is used to represent positiondistribution data corresponding to the pre-planned zero-moment pointplanning trajectory of the biped robot at the current control moment.The zero-moment point planning data includes a lateral planning positionof the zero-moment point that represents a position component of thezero-moment point planning position on the Y axis.

In this process, the biped robot may be simplified into an invertedpendulum model for performing robot dynamics simulation so as toconstruct a walking planning trajectory corresponding to the bipedrobot, then the above-mentioned centroid movement planning trajectory,the pose change trajectory of the two legs of the biped robot, and thezero-moment point planning trajectory may be determined.

In this embodiment, the actual leg support state is used to representthe leg support state of the biped robot at the current control moment.In which, if the current control moment is in the two-leg supportperiod, the actual leg support state is just the two-leg support state;otherwise, if the current control moment is in the single-leg supportperiod, the actual leg support state is just the single-leg supportstate.

The actual movement data of the centroid is used to represent thecentroid data of the centroid of the biped robot at the current controlmoment, which includes an actual horizontal movement position of thecentroid and an actual horizontal movement velocity of the centroid. Theactual horizontal movement position of the centroid represents theactual movement position (including a position component of the actualhorizontal movement position of the centroid on the X axis, and aposition component of the actual horizontal movement position of thecentroid on the Y axis) of the centroid of the robot on the horizontalplane where the X axis and the Y axis are located, and the actualhorizontal movement velocity of the centroid represents the actualmovement velocity (including a velocity component of the actualhorizontal movement velocity of the centroid on the X axis, and avelocity component of the actual horizontal movement velocity of thecentroid on the Y axis) of the centroid of the robot on the horizontalplane where the X axis and the Y axis are located.

The actual position data of the two legs is used to represent the actualpositions of the two legs of the biped robot at the current controlmoment, which includes the actual lateral position of each of the twolegs of the biped robot that represents the position component of theactual position data of the biped robot on the Y axis.

The two-leg actual force data is used to represent the force data of thetwo legs of the biped robot at the current control moment, whichincludes the actual joint torque of the ankle joints (including the leftankle joint and the right ankle joint) of the two legs, a two-leglongitudinal actual force, and a two-leg horizontal actual force. Inwhich, the ankle joint of each leg includes an ankle side joint and anankle anterior joint of the leg, and the actual joint torque of theankle joint of each leg includes an actual joint torque of each of theankle side joint and the front ankle joint of the leg. The two-leglongitudinal actual force includes the magnitude of the external forcesreceived by the two legs on the Z axis; and the two-leg horizontalactual force represents the magnitude of the external forces acting oneach of the two legs on the horizontal plane where the X axis and the Yaxis are located, which includes the value of the external force of eachof the left leg and the right leg on the X-axis, and the value of theexternal force of each of the left and the right leg on the Y-axis.

In this process, the actual leg support state, the actual movement dataof the centroid, the actual position data of the two legs and the actualforce data of the two legs represent the actual motion status of thebiped robot at the current control moment.

S220: calculating an expected support force of the two legs based on thezero-moment point planning data and the actual position data of the twolegs.

In this embodiment, after the robot control apparatus 10 obtains thecurrent zero-moment point planning data and actual position data of thetwo legs of the biped robot, it can extract the zero-moment pointplanned lateral position from the zero-moment point planning data, andextract the actual lateral position of each of the two legs of the bipedrobot from the actual position data of the two leges, so as to combinethe extracted data to calculate the current expected support force ofthe two legs of the biped robot.

FIG. 5 is a flow chart of sub-steps included in step S220 of FIG. 4 . Inthis embodiment, step S220 may include sub-steps S221 and S222 whichaccurately determine the current expected two-leg support force of thebiped robot.

S221: calculating a gravity sharing coefficient of each of the two legsof the biped robot based on a zero-moment point lateral planningposition included in the zero-moment point planning data and an actuallateral position of each of the two legs of the biped robot included inthe actual position data of the two legs.

In this embodiment, the sum of the gravity sharing coefficients of thetwo legs is 1, and the calculation of the gravity sharing coefficient ofthe right leg is as an equation of:

${K_{f} = \frac{❘{p_{yplan} - p_{lf}}❘}{❘{p_{lf} - p_{rf}}❘}};$

where, p_(yplan) represents the lateral planning position of thezero-moment point, p_(lf) represents the actual lateral position of theleft leg, and p_(rf) represents the actual lateral position of the rightleg, where 0<=K_(f)<=1.

S222: calculating the expected support force of the two legs based on amass of the biped robot and the gravity sharing coefficient of each ofthe two legs of the biped robot.

In this embodiment, the expected support force of the two legs mayinclude the expected support force of each of the left leg and the rightleg of the biped robot, and the expected support force of the left legof the biped robot is a product value between the gravity sharingcoefficient of the left leg and the gravity of the biped robot, and theexpected support force of the right leg of the biped robot is a productvalue between the gravity sharing coefficient of the right leg and thegravity of the biped robot. In which, the gravity of the biped robot isa product value between the mass of the biped robot and the currentgravitational acceleration.

Therefore, the present disclosure can accurately determine the currentexpected support force of the two legs of the biped robot related to theactual motion status by performing the above-mentioned sub-step S221 andsub-step S222.

S230: calculating, using a compliance control algorithm, a desired jointposture angle of ankle joints of the two legs based on the expectedsupport force of the two legs, the movement planning data of thecentroid, the actual movement data of the centroid, and the actual forcedata of the two leg.

In this embodiment, the robot control apparatus 10 may combine theobtained movement planning data of the centroid, the actual movementdata of the centroid, and the actual force data of the two legs with thecalculated expected support force of the two legs, and at the legposture dimension level, the compliant control algorithm is used todetermine the current desired joint posture angle of the ankle joints ofthe two legs of the biped robot, so that the posture of the sole of theleg of the robot can be ensured to substantially match the actual groundconditions through the determined desired joint posture angle, therebyimproving the walking stability of the biped robot.

FIG. 6 is a flow chart of sub-steps included in step S230 of FIG. 4 . Inthis embodiment, the step S230 may include sub-steps S231-S235 whichaccurately determine, at the leg posture dimension level, determine thedesired joint posture angle of the ankle joints of the two legs withreference to the current actual motion status of the biped robot that isfor adapting to the actual ground conditions.

S231: calculating a capture point planned horizontal position of thebiped robot at the current moment based on a horizontal movementplanning position of the centroid and a horizontal movement planningvelocity of the centroid that are included in the movement planning dataof the centroid.

In this embodiment, the determination algorithm of capture point in theinverted pendulum model may be expressed as

$\xi_{1} = {{x + {\frac{\overset{˙}{x}}{\omega}{and}\xi_{2}}} = {y + {\frac{\overset{.}{y}}{\omega}.}}}$

In which, ξ₁ is used to represent the position component of a capturepoint position of the biped robot on the X axis, x is used to representthe position component of the inverted pendulum centroid position of thebiped robot on the X axis, and {dot over (x)} is used to represent thevelocity component of the inverted pendulum centroid velocity of thebiped robot on the X axis, ξ₂ is used to represent the positioncomponent of the capture point position of the biped robot on the Yaxis, y is used to represent the inverted pendulum centroid position ofthe biped robot on the Y axis, {dot over (y)} is used to represent thevelocity component of the inverted pendulum centroid velocity of thebiped robot on the Y axis, and ω is used to represent the leg swingfrequency of the biped robot and its value is equal to the square rootof the ratio between the acceleration of gravity and the positioncomponent of the inverted pendulum centroid position on the Z axis.

Therefore, the capture point planned horizontal position may include theposition component of the capture point planned position on the X-axisand that of the capture point planned position on the Y-axis, and theposition component of the horizontal movement planning position of thecentroid on the X-axis and the velocity component of the horizontalmovement planning velocity on the X axis may be substituted into theabove-mentioned equation

$\xi_{1} = {x + \frac{\overset{.}{x}}{\omega}}$

to calculate the position component of the capture point plannedposition on the X axis, and the position component of the horizontalmovement planning position of the centroid on the Y-axis and thevelocity component of the horizontal movement planning velocity on the Yaxis may be substituted into the above-mentioned equation

$\xi_{2} = {y + \frac{\overset{.}{y}}{\omega}}$

to calculate the position component of the capture point plannedposition on the Y axis.

S232: calculating a capture point actual horizontal position of thebiped robot at the current moment based on the actual horizontalmovement position of the centroid and the actual horizontal movementvelocity of the centroid that are included in the actual movement dataof the centroid.

In this embodiment, the capture point actual horizontal position mayinclude a position component of the capture point actual position on theX axis and that of the capture point actual position on the Y axis. Theposition component of the actual horizontal movement position of thecentroid on the X axis and the velocity component of the actualhorizontal movement velocity of the centroid on the X axis nay besubstituted into the above-mentioned equation

$\xi_{1} = {x + \frac{\overset{.}{x}}{\omega}}$

to calculate the position component of the capture point actual positionon the X-axis, and the position component of the actual horizontalmovement position of the centroid on the Y axis and the velocitycomponent of the actual horizontal movement velocity of the centroid onthe Y axis nay be substituted into the above-mentioned equation

$\xi_{2} = {y + \frac{\overset{.}{y}}{\omega}}$

to calculate the position component of the capture point actual positionon the Y-axis.

S233: calculating a capture point position difference between thecapture point planned horizontal position and the capture point actualhorizontal position.

In this embodiment, the capture point position difference may include adifference component of the capture point position difference on the Xaxis and that of the capture point position difference on the Y axis. Inwhich, the position component of the capture point planned position onthe X axis that is included in the capture point planned horizontalposition may be subtracted from the position component of the capturepoint actual position on the X axis that is included in the capturepoint actual horizontal position, so as to obtain the differencecomponent of the capture point position difference on the X axis; andthe position component of the capture point planned position on the Yaxis that is included in the capture point planned horizontal positionmay be subtracted from the position component of the capture pointactual position on the Y axis that is included in the capture pointactual horizontal position, so as to obtain the difference component ofthe capture point position difference on the Y axis.

S234: calculating an expected joint torque of the ankle joints of thetwo legs at the current moment by performing an ankle joint torqueoperation based on the expected support force of the two legs and thecapture point position difference.

In this embodiment, the expected joint torque of the ankle joint of eachleg includes the expected joint torque of the ankle side joint and ankleanterior joint of the leg. At this time, the expected joint torque ofthe ankle side joint of the leg is a product value between the expectedsupport force of the leg and the difference component of the capturepoint position difference on the X-axis, the expected joint torque ofthe ankle anterior joint of the leg is a product value of the expectedsupport force of the leg and the difference component of the capturepoint position difference on the Y-axis.

S235: calculating the desired joint posture angle of the ankle joints ofthe two legs using a first elastic damping control model related tojoint posture angle that corresponds to the ankle joints of the two legsbased on the expected joint torque of the ankle joints of the two legsat the current moment and an actual joint torque of the ankle joints ofthe two legs included in the actual force data of the two legs at thecurrent moment.

In this embodiment, the first elastic damping control model may be as anequation of:

{dot over (R)}=K _(P1)(T _(d) −T _(m))−K _(S1) R;

where, {dot over (R)} represents the expected angular velocity of any ofthe ankle joints of the two legs at the current moment, T_(d) representsthe desired joint posture angle of the ankle joints of the two legs atthe current moment, T_(m) represents the expected joint torque of theankle joint of the leg at the current moment, K_(P1) represents a firstcontroller damping parameter vector for joint posture, and K_(S1)represents a first controller stiffness parameter vector for jointposture, where {dot over (R)} is the first derivative of R.

Therefore, the robot control apparatus 10 may calculate the jointposture angle using the first elastic damping control model bysubstituting the expected joint torque and actual joint torque of thecorresponding joint for the ankle side joint of the left leg, the ankleanterior joint of the left leg, the ankle side joint of the right leg,and the ankle anterior joint of the right leg, so as to obtain thedesired joint posture angles of each of the ankle side joint of the leftleg, the ankle anterior joint of the left leg, the ankle side joint ofthe right leg, and the ankle anterior joint of the right leg, therebyensuring that the of the posture of the sole of the leg of the bipedrobot can substantially match the actual ground conditions under thecondition that the corresponding ankle joints of the two legs maintainthe desired joint posture angle.

Therefore, in the present disclosure, compliant control can be performedon the biped robot at the leg posture dimension level by performing theabove-mentioned sub-steps S231-S235, so as to determine the desiredjoint posture angle of the ankle joints of the two legs with referenceto the current actual motion status of the biped robot that is foradapting to the actual ground conditions.

S240: calculating a desired joint position of the ankle joints of thetwo legs that matches the actual leg support state based on the expectedsupport force of the two legs, the movement planning data of thecentroid, the actual movement data of the centroid, and the actual forcedata of the two legs.

In this embodiment, the robot control apparatus 10 may combine theobtained step planning data and actual force data of the two legs withthe calculated expected support force of the two legs, and calculate, atthe leg position dimension level, the desired joint position of theankle joints of the two legs that matches the actual leg support stateusing the compliance control algorithm, so as to ensure that theposition of the sole of the leg of the robot substantially matches theactual ground conditions through the determined desired joint position,thereby improving the walking stability of the biped robot.

FIG. 7 is a flow chart of sub-steps included in step S240 of FIG. 4 . Asshown in FIG. 4 , in this embodiment, the step S240 may includesub-steps S241-S246 which accurately determine, at the leg positiondimension level, determine the desired joint position of the anklejoints of the two legs with reference to the current actual motionstatus of the biped robot that is for adapting to the actual groundconditions.

S241: calculating an inter-leg support force difference between theexpected support forces of the two legs, and calculating an inter-leglongitudinal force difference between longitudinal actual force valuesof the two legs included in the actual force data of the two legs.

In this embodiment, the inter-leg support force difference may be thedifference between the expected support force of the left leg and thatof the right leg of the biped robot. The inter-leg longitudinal forcedifference may be the difference between the actual longitudinal forceof the left leg and that of the right leg, and the inter-leg horizontalforce difference may be the difference between the actual horizontalforce of the left leg and that of the right leg. The inter-leghorizontal force difference may include a force difference component ofthe inter-leg horizontal force difference on the X-axis, and a forcedifference component of the inter-leg horizontal force difference on theY-axis.

S242: calculating a corresponding expanded length expected variationamount by performing an expanded length variation amount solving using asecond elastic damping control model related to a leg longitudinalextension length that matches the actual leg support state based on theinter-leg support force difference and the inter-leg longitudinal forcedifference.

In this embodiment, the leg longitudinal extension length is used torepresent the length of the biped robot from its hip to the foot on theZ axis, and the second elastic damping control model may be as anequation of:

{dot over (u)} _(Z) =K _(P2)(ΔF _(Z) −ΔF _(dZ))−K _(S2) u _(Z);

where, {dot over (u)}_(Z) represents an expected change speed of the leglongitudinal extension length at the current moment, u_(Z) represents anexpected variation amount of the leg longitudinal extension length atthe current moment, ΔF_(Z) represents the inter-leg support forcedifference, ΔF_(dZ) represents the inter-leg support force difference,K_(P2) represents a second controller damping parameter vector for theleg longitudinal extension length at the current moment, and K_(S2)represents a second controller stiffness parameter vector for the leglongitudinal extension length that matches the actual leg support state,where {dot over (u)}_(Z) is the first derivative of u_(Z).

FIG. 8 is a schematic diagram of the stiffness adjustment of a secondelastic damping control model according to an embodiment of the presentdisclosure. As shown in FIG. 8 , in this embodiment, the values of theparameter vector of the second controller stiffness parameter vector ofthe second elastic damping control model are different in the timeperiods corresponding to different leg support states. In which, thevalue of the parameter vector of the second controller stiffnessparameter vector in the two-leg support period (i.e., the time period inwhich the actual leg support state is the two-leg support state) is lessthan that of the second controller stiffness parameter vector in thesingle-leg support period (i.e., the time period in which the actual legsupport state is the single-leg support state).

If the current control moment of the biped robot is within the two-legsupport period, the robot control apparatus 10 may realize the lowstiffness compliant control of the longitudinal position of the sole ofthe leg through the second controller stiffness parameter vector thatcurrently has a small value, so that the biped robot has enough strengthto realize the tracking of the expected force in the two-leg supportstate so as to reduce the impact of the force, thereby realizing theadaptation of the sole of the leg to the terrain of the ground.

If the current control moment of the biped robot is within thesingle-leg support period, the robot control apparatus 10 can realizethe high-stiffness compliant control of the longitudinal position of thesole of the leg through the second controller stiffness parameter vectorthat currently has a large value, so that the biped robot has enoughstrength to cause the longitudinal extending length of the leg torestore to the default state in the single-leg support state.

S243: calculating a corresponding inter-leg horizontal position expectedvariation amount by performing a positional variation amount solvingusing a third elastic damping control model related to an inter-leghorizontal position difference that matches the actual leg support statebased on the inter-leg horizontal force difference and an expectedinter-leg horizontal internal force difference included in the stepplanning data of the two legs.

In this embodiment, the inter-leg horizontal position difference is usedto represent the position difference between the two legs on thehorizontal plane where the X-axis and the Y-axis are located. Theinter-leg horizontal position expected variation amount may include avariation amount component of the inter-leg horizontal position expectedvariation amount on the X-axis, and that of the inter-leg horizontalposition expected variation amount on the Y-axis. In which, the thirdelastic damping control model may be as an equation of:

{dot over (u)} _(L) =K _(P3)(ΔF _(dL) −ΔF _(L))−K _(S3) u _(L);

where, {dot over (u)}_(L) represents an expected change speed of aninter-leg horizontal position of the inter-leg horizontal positiondifference at the current moment, u_(L) represents the inter-leghorizontal position expected variation amount of the inter-leghorizontal position difference at the current moment, ΔF_(L) representsthe inter-leg horizontal force difference, ΔF_(dL) represents theexpected inter-leg horizontal internal force difference, K_(P3)represents a third controller damping parameter vector for the inter-leghorizontal position difference, and K_(S3) represents a third controllerstiffness parameter vector for the inter-leg horizontal positiondifference that matches the actual leg support state, where {dot over(u)}_(L) is the first derivative of u_(L).

FIG. 9 is a schematic diagram of the stiffness adjustment of a thirdelastic damping control model according to an embodiment of the presentdisclosure. As shown in FIG. 9 , in this embodiment, the values of theparameter vector of the third controller stiffness parameter vector ofthe third elastic damping control model are different in the timeperiods corresponding to different leg support states. In which, thevalue of the parameter vector of the third controller stiffnessparameter vector in the two-leg support period (i.e., the time period inwhich the actual leg support state is the two-leg support state) is lessthan that of the third controller stiffness parameter vector in thesingle-leg support period (i.e., the time period in which the actual legsupport state is the single-leg support state).

If the current control moment of the biped robot is within the two-legsupport period, the robot control apparatus 10 can realize the lowstiffness compliant control of the horizontal position of the solethrough the third controller stiffness parameter vector that currentlyhas a small value, so that the biped robot can effectively cause thedistance between the two legs in the horizontal plane to restore to thedefault state in the two-leg support state, and simultaneously eliminatethe internal force between the two legs in the horizontal plane.

If the current control moment of the biped robot is within thesingle-leg support period, the robot control apparatus 10 can realizethe high stiffness compliant control of the horizontal position of thesole through the third controller stiffness parameter vector thatcurrently has a large value, so that the biped robot can effectivelycause the distance between the two legs in the horizontal plane torestore to the default state in the single-leg support state, andsimultaneously eliminate the internal force between the two legs in thehorizontal plane.

In this case, the robot control apparatus 10 may calculate, using theabove-mentioned third elastic damping control model, the variationamount component of the inter-leg horizontal position expected variationamount on the Y-axis by substituting the force difference component ofthe inter-leg horizontal force difference on the X-axis, the internalforce difference component of the inter-leg horizontal expected internalforce difference on the X-axis, the parameter vector component of thethird controller damping parameter vector on the X-axis, and theparameter vector component of the third controller stiffness parametervector on the X axis.

At the same time, the robot control apparatus 10 may calculate, usingthe above-mentioned third elastic damping control model, the variationamount component of the inter-leg horizontal position expected variationamount on the Y-axis by substituting the force difference component ofthe inter-leg horizontal force difference on the Y-axis, the internalforce difference component of the inter-leg horizontal expected internalforce difference on the Y-axis, the parameter vector component of thethird controller damping parameter vector on the Y axis, and theparameter vector component of the third controller stiffness parametervector on the Y-axis.

S244: calculating an expected longitudinal position variation amount ofthe ankle joints of the two legs at the current moment based on theexpanded length expected variation amount, and calculating an expectedhorizontal position variation amount of the ankle joints of the two legsbased on the inter-leg horizontal position expected variation amount.

In this embodiment, the expected variation amount of the currentlongitudinal position of the left ankle joint may be obtained bymultiplying the expanded length expected variation amount by −0.5, andthe expected variation amount of the current longitudinal position ofthe right ankle joint may be obtained by multiplying the expanded lengthexpected variation amount by 0.5.

At the same time, the variation amount component of the expectedvariation amount of the current horizontal position of the left anklejoint on the X-axis may be obtained by multiplying the variation amountcomponent of the inter-leg horizontal position expected variation amounton the X-axis by −0.5, the variation amount component of the expectedvariation amount of the current horizontal position of the right anklejoint on the X-axis may be obtained by multiplying the variation amountcomponent of the inter-leg horizontal position expected variation amounton the X-axis by 0.5.

The variation amount component of the expected variation amount of thecurrent horizontal position of the left ankle joint on the Y-axis may beobtained by multiplying the variation amount component of the inter-leghorizontal position expected variation amount on the Y-axis by −0.5, thevariation amount component of the expected variation amount of thecurrent horizontal position of the right ankle joint on the Y-axis maybe obtained by multiplying the variation amount component of theinter-leg horizontal position expected variation amount on the Y-axis by0.5.

S245: calculating an expected joint longitudinal position included inthe desired joint position by performing a positional superimposeadjustment on a joint longitudinal planning position included in thestep planning data of the two legs based on the expect longitudinalposition variation amount of the ankle joints of the two legs at thecurrent moment.

In this embodiment, the robot control apparatus 10 may obtain theexpected joint longitudinal position of the left ankle joint bysuperimposing and adjusting the current expected variation amount of thelongitudinal position of the left ankle joint and the joint longitudinalplanned position of the left ankle joint, and obtain the expected jointlongitudinal position of the right ankle joint by superimposing andadjusting the current expected variation amount of the longitudinalposition of the of the longitudinal position of the right ankle jointand the joint longitudinal planned position of the right ankle joint.

S246: calculating an expected joint horizontal position included in thedesired joint position by performing the positional superimposeadjustment on a joint horizontal planning position included in the stepplanning data of the two legs based on the expect horizontal positionvariation amount of the ankle joints of the two legs at the currentmoment.

In this embodiment, the robot control apparatus 10 may obtain theposition component of the horizontal expected position of the left anklejoint on the X-axis by superimposing and adjusting the variation amountcomponent of the current expected variation amount of the horizontalposition of the left ankle joint on the X-axis and the positioncomponent of the joint horizontal planned position of the left anklejoint on the X-axis, and may obtain the position component of thehorizontal expected position of the left ankle joint on the Y-axis bysuperimposing and adjusting the variation amount component of thecurrent expected variation amount of the horizontal position of the leftankle joint on the Y-axis and the position component of the jointhorizontal planned position of the left ankle joint on the Y-axis.

At the same time, the robot control apparatus 10 may further obtain theposition component of the horizontal expected position of the rightankle joint on the X-axis by superimposing and adjusting the variationamount component of the current expected variation amount of thehorizontal position of the right ankle joint on the X-axis and theposition component of the joint horizontal planned position of the rightankle joint on the X-axis, and may obtain the position component of thehorizontal expected position of the right ankle joint on the Y-axis bysuperimposing and adjusting the variation amount component of thecurrent expected variation amount of the horizontal position of theright ankle joint on the Y-axis and the position component of the jointhorizontal planned position of the right ankle joint on the Y-axis.

Therefore, in the present disclosure, compliant control can be performedon the biped robot at the leg posture dimension level by performing theabove-mentioned sub-steps S241-S246 to determine the desired jointposition of the ankle joints of the two legs with reference to thecurrent actual motion status of the biped robot that is for adapting tothe actual ground conditions, so as to ensure that the position of thesole of the leg of the robot substantially matches the actual groundcondition when the corresponding ankle joints of the two legs maintainsthe desired joint position, thereby improving the walking stability andthe terrain adaptability of the biped robot.

S250: controlling the biped robot to perform a stepping motion accordingto the desired joint posture angle and the desired joint position of theankle joints of the two legs.

In this embodiment, after the robot control apparatus 10 calculates thedesired joint posture angle and desired joint positions that canmaintain the pose of the sole of the leg of the robot substantiallymatching the actual ground conditions, it can correspondingly controlthe joint structures contained in the biped robots to cooperate witheach other to cause the ankle joints of the two legs of the biped robotto exhibit the desired joint posture angle and the desired jointposition, so as to effectively reduce the landing impact force of thebiped robot during the single-leg support period and effectively reducethe inter-leg internal force of the biped robot during the two-legsupport period, thereby improving the walking stability and terrainadaptability of the biped robot.

Therefore, in the present disclosure, all-direction compliant controlcan be performed on the biped robot at the leg position dimension levelaccording to the actual motion status of the biped robot during thewalking process of the biped robot by performing the above-mentionedsub-steps S210-S250, so that the desired leg pose condition (includingthe desired leg position and the desired leg posture) of the biped robotsubstantially matches the actual ground condition, so as to effectivelyreduce the landing impact force of the biped robot during the single-legsupport period through the desired leg pose condition and effectivelyreduce the inter-leg internal force of the biped robot during thetwo-leg support period, thereby improving the walking stability andterrain adaptability of the biped robot.

In the present disclosure, in order to ensure that the robot controlapparatus 10 can perform the above-mentioned robot step control methodthrough the robot step controller 100, the forgoing functions isimplemented by dividing the robot step controller 100 into functionalmodules. The specific composition of the robot step controller 100provided in the present disclosure will be described accordingly below.

FIG. 10 is a schematic block diagram of the structure of a robot stepcontroller according to an embodiment of the present disclosure. Asshown in FIG. 10 , in this embodiment, a robot step controller 100 isprovided. The robot step controller 100 may include a step dataobtaining module 110, a two-leg support calculation module 120, a wo-legposture calculation module 130, a wo-leg position calculation module140, and a step motion control module 150.

The step data obtaining module 110 is configured to obtain movementplanning data of a centroid of the biped robot, step planning data oftwo legs of the biped robot and zero-moment point planning data of thebiped robot at a current moment, and an actual leg support state, actualmovement data of the centroid, actual position data of the two legs andactual force data of the two legs at the current moment.

The two-leg support calculation module 120 is configured to calculate anexpected support force of the two legs based on the zero-moment pointplanning data and the actual position data of the two legs.

The wo-leg posture calculation module 130 is configured to calculate,using a compliance control algorithm, a desired joint posture angle ofankle joints of the two legs based on the expected support force of thetwo legs, the movement planning data of the centroid, the actualmovement data of the centroid, and the actual force data of the twolegs.

The wo-leg position calculation module 140 is configured to calculate adesired joint position of the ankle joints of the two legs that matchesthe actual leg support state based on the expected support force of thetwo legs, the movement planning data of the centroid, the actualmovement data of the centroid, and the actual force data of the twolegs.

The step motion control module 150 is configured to control the bipedrobot to perform a stepping motion according to the desired jointposture angle and the desired joint position of the ankle joints of thetwo legs.

It should be noted that, the robot step control 100 provided by thisembodiment has the same basic principles and technical effects as theabove-mentioned robot step control method. For a brief description, forparts not mentioned in this embodiment, reference may be made to theforgoing description of the robot step control method.

In addition, in the embodiments of the present disclosure, anon-transitory storage medium may also be provided, so as to store thecomputer program expressed in the form of a software product in theforgoing technical solution of the present disclosure through thestorage medium. In which, the computer program may include a pluralityof instructions to enable a computer device (which may be a personalcomputer, a server, a network device, or the like) to execute all orpart of the steps of the robot step control method corresponding to eachembodiment of the present disclosure. The above-mentioned storage mediumincludes a variety of media such as a USB disk, a mobile hard disk, aread-only memory (ROM), a random access memory (RAM), a magnetic disk,and an optical disk which is capable of storing program codes.

In summary, in the robot step control method and apparatus, the robotcontrol apparatus, and the storage medium provided by the presentdisclosure, it determines the corresponding expected support force ofthe two legs according to the zero-moment point planning data and theactual position data of the two legs of the biped robot at the currentmoment, and calculates the current desired joint posture angle of theankle joints of the two legs using the compliance control algorithmbased on the expected support force of the two legs and the movementplanning data of the centroid, the actual movement data of the centroidand the actual force data of the two legs of the biped robot at thecurrent moment, and then calculates the desired joint position of theankle joints of the two legs that matches the current actual leg supportstate using the compliance control algorithm based on the step planningdata of the two legs, the expected support force of the two legs, andthe actual force data of the two legs of the biped robot at the currentmoment, so as to control the biped robot to perform the stepping motionaccording to the desired joint pose condition of the ankle joints of thetwo legs. In such manner, all-direction compliant controls can beperformed on the desired leg pose condition according to the actualmotion status of the biped robot, so that both the desired leg positionand the desired leg posture are substantially matched with the actualground conditions so as to reduce the landing impact force of the bipedrobot during the single-leg support period and the inter-leg internalforce of the biped robot during the two-leg support period, therebyimproving the walking stability and terrain adaptability of the bipedrobot.

The forgoing is only various embodiments of the present disclosure,while the scope of the present disclosure is not limited thereto. Forthose skilled in the art, equivalent modifications or replacements thatcan be easily conceived within the technical scope of the presentdisclosure should be included within the scope of the presentdisclosure. Therefore, the scope of the present disclosure should bedetermined in accordance with the scope of the claims.

What is claimed is:
 1. A computer-implemented step control method for abiped robot, comprising: obtaining movement planning data of a centroidof the biped robot, step planning data of two legs of the biped robotand zero-moment point planning data of the biped robot at a currentmoment, and an actual leg support state, actual movement data of thecentroid, actual position data of the two legs and actual force data ofthe two legs at the current moment; calculating an expected supportforce of the two legs based on the zero-moment point planning data andthe actual position data of the two legs; calculating, using acompliance control algorithm, a desired joint posture angle of anklejoints of the two legs based on the expected support force of the twolegs, the movement planning data of the centroid, the actual movementdata of the centroid, and the actual force data of the two legs;calculating a desired joint position of the ankle joints of the two legsthat matches the actual leg support state based on the expected supportforce of the two legs, the movement planning data of the centroid, theactual movement data of the centroid, and the actual force data of thetwo legs; and controlling the biped robot to perform a stepping motionaccording to the desired joint posture angle and the desired jointposition of the ankle joints of the two legs.
 2. The method of claim 1,wherein the calculating the expected support force of the two legs basedon the zero-moment point planning data and the actual position data ofthe two legs comprises: calculating a gravity sharing coefficient ofeach of the two legs of the biped robot based on a zero-moment pointlateral planning position included in the zero-moment point planningdata and an actual lateral position of each of the two legs of the bipedrobot included in the actual position data of the two legs; andcalculating the expected support force of the two legs based on a massof the biped robot and the gravity sharing coefficient of each of thetwo legs of the biped robot.
 3. The method of claim 1, wherein thecalculating, using the compliance control algorithm, the desired jointposture angle of the ankle joints of the two legs based on the expectedsupport force of the two legs, the movement planning data of thecentroid, the actual movement data of the centroid, and the actual forcedata of the two legs comprises: calculating a capture point plannedhorizontal position of the biped robot at the current moment based on ahorizontal movement planning position of the centroid and a horizontalmovement planning velocity of the centroid that are included in themovement planning data of the centroid; calculating a capture pointactual horizontal position of the biped robot at the current momentbased on the actual horizontal movement position of the centroid and theactual horizontal movement velocity of the centroid that are included inthe actual movement data of the centroid; calculating a capture pointposition difference between the capture point planned horizontalposition and the capture point actual horizontal position; calculatingan expected joint torque of the ankle joints of the two legs at thecurrent moment by performing an ankle joint torque operation based onthe expected support force of the two legs and the capture pointposition difference; and calculating the desired joint posture angle ofthe ankle joints of the two legs using a first elastic damping controlmodel related to joint posture angle that corresponds to the anklejoints of the two legs based on the expected joint torque of the anklejoints of the two legs at the current moment and an actual joint torqueof the ankle joints of the two legs included in the actual force data ofthe two legs at the current moment.
 4. The method of claim 3, whereinthe first elastic damping control model is as an equation of:{dot over (R)}=K _(P1)(T _(d) −T _(m))−K _(S1) R; where, {dot over (R)}represents the expected angular velocity of any of the ankle joints ofthe two legs at the current moment, T_(d) represents the desired jointposture angle of the ankle joints of the two legs at the current moment,T_(m) represents the expected joint torque of the ankle joint of the legat the current moment, K_(P1) represents a first controller dampingparameter vector for joint posture, and K_(S1) represents a firstcontroller stiffness parameter vector for joint posture, where {dot over(R)} is the first derivative of R.
 5. The method of claim 1, wherein thecalculating the desired joint position of the ankle joints of the twolegs that matches the actual leg support state based on the expectedsupport force of the two legs, the movement planning data of thecentroid, the actual movement data of the centroid, and the actual forcedata of the two legs comprises: calculating an inter-leg support forcedifference between the expected support forces of the two legs, andcalculating an inter-leg longitudinal force difference betweenlongitudinal actual force values of the two legs included in the actualforce data of the two legs; calculating a corresponding expanded lengthexpected variation amount by performing an expanded length variationamount solving using a second elastic damping control model related to aleg longitudinal extension length that matches the actual leg supportstate based on the inter-leg support force difference and the inter-leglongitudinal force difference; calculating a corresponding inter-leghorizontal position expected variation amount by performing a positionalvariation amount solving using a third elastic damping control modelrelated to an inter-leg horizontal position difference that matches theactual leg support state based on the inter-leg horizontal forcedifference and an expected inter-leg horizontal internal forcedifference included in the step planning data of the two legs;calculating an expected longitudinal position variation amount of theankle joints of the two legs at the current moment based on the expandedlength expected variation amount, and calculating an expected horizontalposition variation amount of the ankle joints of the two legs based onthe inter-leg horizontal position expected variation amount; calculatingan expected joint longitudinal position included in the desired jointposition by performing a positional superimpose adjustment on a jointlongitudinal planning position included in the step planning data of thetwo legs based on the expect longitudinal position variation amount ofthe ankle joints of the two legs at the current moment; and calculatingan expected joint horizontal position included in the desired jointposition by performing the positional superimpose adjustment on a jointhorizontal planning position included in the step planning data of thetwo legs based on the expect horizontal position variation amount of theankle joints of the two legs at the current moment.
 6. The method ofclaim 5, wherein the second elastic damping control model is as anequation of:{dot over (u)} _(Z) =K _(P2)(ΔF _(Z) −ΔF _(dZ))−K _(S2) u _(Z); where,{dot over (u)}_(Z) represents an expected change speed of the leglongitudinal extension length at the current moment, u_(Z) represents anexpected variation amount of the leg longitudinal extension length atthe current moment, ΔF_(Z) represents the inter-leg support forcedifference, ΔF_(dZ) represents the inter-leg support force difference,K_(P2) represents a second controller damping parameter vector for theleg longitudinal extension length at the current moment, and K_(S2)represents a second controller stiffness parameter vector for the leglongitudinal extension length that matches the actual leg support state,where {dot over (u)}_(Z) is the first derivative of u_(Z), the actualleg support state is that the second controller stiffness parametervector in a single-leg support state of the robot is larger than thesecond controller stiffness parameter when the actual leg support stateis a two leg support state of the robot.
 7. The method of claim 5,wherein the third elastic damping control model is as an equation of:{dot over (u)} _(L) =K _(P3)(ΔF _(dL) −ΔF _(L))−K _(S3) u _(L); where,{dot over (u)}_(L) represents an expected change speed of an inter-leghorizontal position of the inter-leg horizontal position difference atthe current moment, u_(L) represents the inter-leg horizontal positionexpected variation amount of the inter-leg horizontal positiondifference at the current moment, ΔF_(L) represents the inter-leghorizontal force difference, ΔF_(dL) represents the expected inter-leghorizontal internal force difference, K_(P3) represents a thirdcontroller damping parameter vector for the inter-leg horizontalposition difference, and K_(S3) represents a third controller stiffnessparameter vector for the inter-leg horizontal position difference thatmatches the actual leg support state, where {dot over (u)}_(L) is thefirst derivative of u_(L), the actual leg support state is that thethird controller stiffness parameter vector in a single-leg supportstate of the robot is larger than the third controller stiffnessparameter when the actual leg support state is a two leg support stateof the robot.
 8. A robot control apparatus, comprising: a processor; amemory coupled to the processor; and one or more computer programsstored in the memory and executable on the processor; wherein, the oneor more computer programs comprise: instructions for obtaining movementplanning data of a centroid of a biped robot, step planning data of twolegs of the biped robot and zero-moment point planning data of the bipedrobot at a current moment, and an actual leg support state, actualmovement data of the centroid, actual position data of the two legs andactual force data of the two legs at the current moment; instructionsfor calculating an expected support force of the two legs based on thezero-moment point planning data and the actual position data of the twolegs; instructions for calculating, using a compliance controlalgorithm, a desired joint posture angle of ankle joints of the two legsbased on the expected support force of the two legs, the movementplanning data of the centroid, the actual movement data of the centroid,and the actual force data of the two legs; instructions for calculatinga desired joint position of the ankle joints of the two legs thatmatches the actual leg support state based on the expected support forceof the two legs, the movement planning data of the centroid, the actualmovement data of the centroid, and the actual force data of the twolegs; and instructions for controlling the biped robot to perform astepping motion according to the desired joint posture angle and thedesired joint position of the ankle joints of the two legs.
 9. The robotcontrol apparatus of claim 8, wherein the instructions for calculatingthe expected support force of the two legs based on the zero-momentpoint planning data and the actual position data of the two legscomprise: instructions for calculating a gravity sharing coefficient ofeach of the two legs of the biped robot based on a zero-moment pointlateral planning position included in the zero-moment point planningdata and an actual lateral position of each of the two legs of the bipedrobot included in the actual position data of the two legs; andinstructions for calculating the expected support force of the two legsbased on a mass of the biped robot and the gravity sharing coefficientof each of the two legs of the biped robot.
 10. The robot controlapparatus of claim 8, wherein the instructions for calculating, usingthe compliance control algorithm, the desired joint posture angle of theankle joints of the two legs based on the expected support force of thetwo legs, the movement planning data of the centroid, the actualmovement data of the centroid, and the actual force data of the two legscomprise: instructions for calculating a capture point plannedhorizontal position of the biped robot at the current moment based on ahorizontal movement planning position of the centroid and a horizontalmovement planning velocity of the centroid that are included in themovement planning data of the centroid; instructions for calculating acapture point actual horizontal position of the biped robot at thecurrent moment based on the actual horizontal movement position of thecentroid and the actual horizontal movement velocity of the centroidthat are included in the actual movement data of the centroid;instructions for calculating a capture point position difference betweenthe capture point planned horizontal position and the capture pointactual horizontal position; instructions for calculating an expectedjoint torque of the ankle joints of the two legs at the current momentby performing an ankle joint torque operation based on the expectedsupport force of the two legs and the capture point position difference;and instructions for calculating the desired joint posture angle of theankle joints of the two legs using a first elastic damping control modelrelated to joint posture angle that corresponds to the ankle joints ofthe two legs based on the expected joint torque of the ankle joints ofthe two legs at the current moment and an actual joint torque of theankle joints of the two legs included in the actual force data of thetwo legs at the current moment.
 11. The robot control apparatus of claim10, wherein the first elastic damping control model is as an equationof:{dot over (R)}=K _(P1)(T _(d) −T _(m))−K _(S1) R; where, {dot over (R)}represents the expected angular velocity of any of the ankle joints ofthe two legs at the current moment, T_(d) represents the desired jointposture angle of the ankle joints of the two legs at the current moment,T_(m) represents the expected joint torque of the ankle joint of the legat the current moment, K_(P1) represents a first controller dampingparameter vector for joint posture, and K_(S1) represents a firstcontroller stiffness parameter vector for joint posture, where {dot over(R)} is the first derivative of R.
 12. The robot control apparatus ofclaim 8, wherein the instructions for calculating the desired jointposition of the ankle joints of the two legs that matches the actual legsupport state based on the expected support force of the two legs, themovement planning data of the centroid, the actual movement data of thecentroid, and the actual force data of the two legs comprise:instructions for calculating an inter-leg support force differencebetween the expected support forces of the two legs, and calculating aninter-leg longitudinal force difference between longitudinal actualforce values of the two legs included in the actual force data of thetwo legs; instructions for calculating a corresponding expanded lengthexpected variation amount by performing an expanded length variationamount solving using a second elastic damping control model related to aleg longitudinal extension length that matches the actual leg supportstate based on the inter-leg support force difference and the inter-leglongitudinal force difference; instructions for calculating acorresponding inter-leg horizontal position expected variation amount byperforming a positional variation amount solving using a third elasticdamping control model related to an inter-leg horizontal positiondifference that matches the actual leg support state based on theinter-leg horizontal force difference and an expected inter-leghorizontal internal force difference included in the step planning dataof the two legs; instructions for calculating an expected longitudinalposition variation amount of the ankle joints of the two legs at thecurrent moment based on the expanded length expected variation amount,and calculating an expected horizontal position variation amount of theankle joints of the two legs based on the inter-leg horizontal positionexpected variation amount; instructions for calculating an expectedjoint longitudinal position included in the desired joint position byperforming a positional superimpose adjustment on a joint longitudinalplanning position included in the step planning data of the two legsbased on the expect longitudinal position variation amount of the anklejoints of the two legs at the current moment; and instructions forcalculating an expected joint horizontal position included in thedesired joint position by performing the positional superimposeadjustment on a joint horizontal planning position included in the stepplanning data of the two legs based on the expect horizontal positionvariation amount of the ankle joints of the two legs at the currentmoment.
 13. The robot control apparatus of claim 12, wherein the secondelastic damping control model is as an equation of:{dot over (u)} _(Z) =K _(P2)(ΔF _(Z) −ΔF _(dZ))−K _(S2) u _(Z); where,{dot over (u)}_(Z) represents an expected change speed of the leglongitudinal extension length at the current moment, u_(Z) represents anexpected variation amount of the leg longitudinal extension length atthe current moment, ΔF_(Z) represents the inter-leg support forcedifference, ΔF_(dZ) represents the inter-leg support force difference,K_(P2) represents a second controller damping parameter vector for theleg longitudinal extension length at the current moment, and K_(S2)represents a second controller stiffness parameter vector for the leglongitudinal extension length that matches the actual leg support state,where {dot over (u)}_(Z) is the first derivative of u_(Z), the actualleg support state is that the second controller stiffness parametervector in a single-leg support state of the robot is larger than thesecond controller stiffness parameter when the actual leg support stateis a two leg support state of the robot.
 14. The robot control apparatusof claim 12, wherein the third elastic damping control model is as anequation of:{dot over (u)} _(L) =K _(P3)(ΔF _(dL) −ΔF _(L))−K _(S3) u _(L); where,{dot over (u)}_(L) represents an expected change speed of an inter-leghorizontal position of the inter-leg horizontal position difference atthe current moment, u_(L) represents the inter-leg horizontal positionexpected variation amount of the inter-leg horizontal positiondifference at the current moment, ΔF_(L) represents the inter-leghorizontal force difference, ΔF_(dL) represents the expected inter-leghorizontal internal force difference, K_(P3) represents a thirdcontroller damping parameter vector for the inter-leg horizontalposition difference, and K_(S3) represents a third controller stiffnessparameter vector for the inter-leg horizontal position difference thatmatches the actual leg support state, where {dot over (u)}_(L) is thefirst derivative of u_(L), the actual leg support state is that thethird controller stiffness parameter vector in a single-leg supportstate of the robot is larger than the third controller stiffnessparameter when the actual leg support state is a two leg support stateof the robot.
 15. A non-transitory computer-readable storage medium forstoring one or more computer programs, wherein the one or more computerprograms comprise: instructions for obtaining movement planning data ofa centroid of a biped robot, step planning data of two legs of the bipedrobot and zero-moment point planning data of the biped robot at acurrent moment, and an actual leg support state, actual movement data ofthe centroid, actual position data of the two legs and actual force dataof the two legs at the current moment; instructions for calculating anexpected support force of the two legs based on the zero-moment pointplanning data and the actual position data of the two legs; instructionsfor calculating, using a compliance control algorithm, a desired jointposture angle of ankle joints of the two legs based on the expectedsupport force of the two legs, the movement planning data of thecentroid, the actual movement data of the centroid, and the actual forcedata of the two legs; instructions for calculating a desired jointposition of the ankle joints of the two legs that matches the actual legsupport state based on the expected support force of the two legs, themovement planning data of the centroid, the actual movement data of thecentroid, and the actual force data of the two legs; and instructionsfor controlling the biped robot to perform a stepping motion accordingto the desired joint posture angle and the desired joint position of theankle joints of the two legs.
 16. The storage medium of claim 15,wherein the instructions for calculating the expected support force ofthe two legs based on the zero-moment point planning data and the actualposition data of the two legs comprise: instructions for calculating agravity sharing coefficient of each of the two legs of the biped robotbased on a zero-moment point lateral planning position included in thezero-moment point planning data and an actual lateral position of eachof the two legs of the biped robot included in the actual position dataof the two legs; and instructions for calculating the expected supportforce of the two legs based on a mass of the biped robot and the gravitysharing coefficient of each of the two legs of the biped robot.
 17. Thestorage medium of claim 15, wherein the instructions for calculating,using the compliance control algorithm, the desired joint posture angleof the ankle joints of the two legs based on the expected support forceof the two legs, the movement planning data of the centroid, the actualmovement data of the centroid, and the actual force data of the two legscomprise: instructions for calculating a capture point plannedhorizontal position of the biped robot at the current moment based on ahorizontal movement planning position of the centroid and a horizontalmovement planning velocity of the centroid that are included in themovement planning data of the centroid; instructions for calculating acapture point actual horizontal position of the biped robot at thecurrent moment based on the actual horizontal movement position of thecentroid and the actual horizontal movement velocity of the centroidthat are included in the actual movement data of the centroid;instructions for calculating a capture point position difference betweenthe capture point planned horizontal position and the capture pointactual horizontal position; instructions for calculating an expectedjoint torque of the ankle joints of the two legs at the current momentby performing an ankle joint torque operation based on the expectedsupport force of the two legs and the capture point position difference;and instructions for calculating the desired joint posture angle of theankle joints of the two legs using a first elastic damping control modelrelated to joint posture angle that corresponds to the ankle joints ofthe two legs based on the expected joint torque of the ankle joints ofthe two legs at the current moment and an actual joint torque of theankle joints of the two legs included in the actual force data of thetwo legs at the current moment.
 18. The storage medium of claim 17,wherein the first elastic damping control model is as an equation of:{dot over (R)}=K _(P1)(T _(d) −T _(m))−K _(S1) R; where, {dot over (R)}represents the expected angular velocity of any of the ankle joints ofthe two legs at the current moment, T_(d) represents the desired jointposture angle of the ankle joints of the two legs at the current moment,T_(m) represents the expected joint torque of the ankle joint of the legat the current moment, K_(P1) represents a first controller dampingparameter vector for joint posture, and K_(S1) represents a firstcontroller stiffness parameter vector for joint posture, where {dot over(R)} is the first derivative of R.
 19. The storage medium of claim 15,wherein the instructions for calculating the desired joint position ofthe ankle joints of the two legs that matches the actual leg supportstate based on the expected support force of the two legs, the movementplanning data of the centroid, the actual movement data of the centroid,and the actual force data of the two legs comprise: instructions forcalculating an inter-leg support force difference between the expectedsupport forces of the two legs, and calculating an inter-leglongitudinal force difference between longitudinal actual force valuesof the two legs included in the actual force data of the two legs;instructions for calculating a corresponding expanded length expectedvariation amount by performing an expanded length variation amountsolving using a second elastic damping control model related to a leglongitudinal extension length that matches the actual leg support statebased on the inter-leg support force difference and the inter-leglongitudinal force difference; instructions for calculating acorresponding inter-leg horizontal position expected variation amount byperforming a positional variation amount solving using a third elasticdamping control model related to an inter-leg horizontal positiondifference that matches the actual leg support state based on theinter-leg horizontal force difference and an expected inter-leghorizontal internal force difference included in the step planning dataof the two legs; instructions for calculating an expected longitudinalposition variation amount of the ankle joints of the two legs at thecurrent moment based on the expanded length expected variation amount,and calculating an expected horizontal position variation amount of theankle joints of the two legs based on the inter-leg horizontal positionexpected variation amount; instructions for calculating an expectedjoint longitudinal position included in the desired joint position byperforming a positional superimpose adjustment on a joint longitudinalplanning position included in the step planning data of the two legsbased on the expect longitudinal position variation amount of the anklejoints of the two legs at the current moment; and instructions forcalculating an expected joint horizontal position included in thedesired joint position by performing the positional superimposeadjustment on a joint horizontal planning position included in the stepplanning data of the two legs based on the expect horizontal positionvariation amount of the ankle joints of the two legs at the currentmoment.
 20. The storage medium of claim 19, wherein the second elasticdamping control model is as an equation of:{dot over (u)} _(Z) =K _(P2)(ΔF _(Z) −ΔF _(dZ))−K _(S2) u _(Z); where,{dot over (u)}_(Z) represents an expected change speed of the leglongitudinal extension length at the current moment, u_(Z) represents anexpected variation amount of the leg longitudinal extension length atthe current moment, ΔF_(Z) represents the inter-leg support forcedifference, ΔF_(dZ) represents the inter-leg support force difference,K_(P2) represents a second controller damping parameter vector for theleg longitudinal extension length at the current moment, and K_(S3)represents a second controller stiffness parameter vector for the leglongitudinal extension length that matches the actual leg support state,where {dot over (u)}_(Z) is the first derivative of u_(Z), the actualleg support state is that the second controller stiffness parametervector in a single-leg support state of the robot is larger than thesecond controller stiffness parameter when the actual leg support stateis a two leg support state of the robot.